Claude Sonnet 5 Is Here — But That ‘Same Price’ Claim Hides a 30% Cost Surprise
Reading Time: 5 minutesClaude Sonnet 5 launched on 30 June 2026 with near-Opus 4.8 performance, a 1 million token context window, and adaptive thinking enabled by default — but a new tokenizer makes English-language inputs roughly 30 to 42 percent more expensive in real terms than the headline price suggests. Simon Willison’s analysis documents the tokenizer gap empirically, and Indian professionals using Claude-powered tools should audit their costs before the introductory discount expires on 31 August 2026.